One story Herodotus
tells about the origin of the Scythians makes Hercules
and Echidna their ancestors: Herodotus 4.8-12
From thence Heracles came to the land now called Scythia.... [A]t last he came to the region which is called Hylaia; and there he found in a cave a kind of twofold creature formed by the union of a maiden and a serpent, whose upper parts from the buttocks upwards were those of a woman, but her lower parts were those of a snake. Having seen her and marvelled at her, he asked her then whether she had seen any mares straying anywhere; and she said that she had them herself and would not give them up until he lay with her; and Heracles lay with her on condition of receiving them. She then tried to put off the giving back of the mares, desiring to have Heracles with her as long as possible, while he on the other hand desired to get the mares and depart; and at last she gave them back and said: "These mares when they came hither I saved for thee, and thou didst give me reward for saving them; for I have by thee three sons. Tell me then, what must I do with these when they shall be grown to manhood, whether I shall settle them here, for over this land I have power alone, or send them away to thee?"
She thus asked of him, and he, they say, replied: "When thou seest that the boys are grown to men, do this and thou shalt not fail of doing right: -- whichsoever of them thou seest able to stretch this bow as I do now, and to be girded [12a] with this girdle, him cause to be the settler of this land; but whosoever of them fails in the deeds which I enjoin, send him forth out of the land: and if thou shalt do thus, thou wilt both have delight thyself and perform that which has been enjoined to thee." ... And two of her sons, Agathyrsos and Gelonos, not having proved themselves able to attain to the task set before them, departed from the land, being cast out by her who bore them; but Skythes the youngest of them performed the task and remained in the land: and from Skythes the son of Heracles were descended, they say, the succeeding kings of the Scythians (Skythians): and they say moreover that it is by reason of the cup that the Scythians still even to this day wear cups attached to their girdles: and this alone his mother contrived for Skythes.